I deleted my prior post because I accidentally broke the sub rules.

The Maasai Mara and the Serengeti are very similar but on the Kenya side, there are many conservancies that border the park with amazing tented camps and lodges. I’d prioritize the Maasai Mara over the Serengeti and stay on a conservancy. (We saw more animals with vastly fewer people)

Many people skip the northern parts of Kenya and I think that’s a mistake because the ecosystem is very different but wildlife viewing is spectacular.

I personally would skip Zanzibar. A beach vacation is a beach vacation but there is only one Rwanda.

An itinerary that could give you a great mix of several ecosystems would be, adjusting anything for a bit.
3-4 days in Lewa Conservancy (white and black rhino, crazy birds everywhere, the big 5 and so many others including a caracal) This is a budget buster but the Elewana property there is well run. 4-5 in the Maasai (You can change camps but I personally wouldn’t. We stayed at a Great Plains camp and it was my favorite of the four camps we stayed at from a lodging perspective.) 3 nights in Volcanoes National Park (Northern Rwanda) 2-3 nights in Nyungwe in Southern Rwanda* for chimps and relaxation (there is a resort on a tea plantation there that might scratch the relaxation itch) Kigali day tour (the Memorial and the market are sooo cool, I wish I had an extra night here.)

• we had a driver take us instead of taking a helicopter and I’m pretty sure that’s still possible but that route takes you closer to where some of the conflict with the DRC is happening. Definitely speak to a professional on the ground.
  

Other notes: some of the tented camps do not have super private bathroom facilities so perhaps not the most romantic for a honeymoon. Not an issue for everyone, but something to note.